I've a Samsung Galaxy I5510 with Android 2.2 FroYo. It has about 160MB of internal storage. Right now I have only 16.79MB free (according to what Android Settings show) and I want to find out what is using more than 140MB. So I started looking for some apps which can provide some more info. I'd already installed app2sd so I sum all the apps under "phone only" and under "movable". The don't get to 50MB. So I'm still missing about 90MB here. In the SD card app2sd shows 53MB. I installed DiskUsage and when I select "Applications storage" it shows: 113.7MiB in apps 42.8MiB in System data 16.7MiB free. But the problem is in those 113.7MiB, it is also including SD apps. How can I really find out how many storage is using each app or info. so I can decide what to get rid of? Also: The math doesn't close: 113.7MB in apps - 53MB in the sd + 42.8MB system data + 16.7MB free = 120,2MB, not 160! Thanks! Diego Note: I found this and this answer. After someone says he may have corrupted the FAT and suggest a factory reset. IF my problem is that the FAT is corrupted, is the factory reset the only way out? Will the factory reset make me lose my guarantee or may break my phone as rooting it? How can avoid losing contacts (including the linking of them), text messages, all the apps (installed in the phone or in the SD card) and the phone and apps settings?